Mars space exploration

Vic Viola (‘What good is sending astronauts to Mars?’, July 11) writes: “President Bush’s initiative to build a space station on the moon as a base for a manned mission to Mars cannot be justified scientifically, economically or from the standpoint of astronaut safety.” He somehow forgets the most important reason of all, articulated decades ago by the late Isaac Asimov (‘The Stars In Their Courses’): “If humans fail to leave this world, they leave themselves open to extermination by any massive asteroid. Far better not to keep all our species’ “eggs” in one fragile basket!”

One planet-sterilizing impact, with an asteroid > 7- 8 km diameter, is all it would take to remove the human species from the scene. It makes sense therefore to use manned space exploration to expedite our departure from Earth.

Robot probes are clearly cheaper, but they won’t save us when the “Big One” strikes!